We have continued our study of lambda hin function. It causes several alterations in host physiology (transformation). These may reflect effects of hin on the host membrane. hin has been mapped genetically to two regions on lambda. Each of the two genes can independently cause the hin effects. Studies of mRNA in vivo have revealed that two promoters pI and pE are closely related and require cII protein as a positive regulator for initiation. pI initiates transcripts of the Int gene; pE the cI repressor gene of lambda. Int transcription from pI terminates at a rho independent terminator tI 260 bases beyond int. A second promoter pL also transcribes int. It is prevented from terminating at tI by action of another factor, N protein of lambda.